Without commenting on whatever sins the ITM may have committed (as I have no personal knowledge of the situation), I must point out that the most important factor to museum longevity is the need to own the land you occupy, even if it means other progress must wait. Look what happened to PLA at Point Richmond; arguably, moving to Niles Canyon might be the best thing that ever happened to them, but their progress was set back for years and they can still be evicted from their current site. It's often not that simple--look how Perris has expanded out to meet OERM--but owning title to your property makes the future much more secure.